The apparatus comprises of a wooden tube, with large see through holes at both ends, a solid block, and a wooden wand. The cube is placed in the tube, visible at all times through the hole. The wand is passed through the cube and tube, locking the cube firmly in the tube. Then with a tap, the cube visibly penetrates off the wand. The tube can then be opened to show the inside!

There have been similar effects before, but none so clean and convincing. And the best part is that you have almost nothing to do, other than follow the instructions. The effect almost works itself.